Heath's 1913 Aristarchus of Samos is an interesting look at one small aspect of ancient astronomy: the angular size of the sun. Yet to get to this point, Heath needs to review much of the Greek astronomy up to the 3rd century BC. Thus Part 1, the first 298 pages of this work, contains a discussion of astronomical material before Aristarchus. The review, of course, is a bit old, and I would reccomend that anyone interested in the technical aspects of ancient Greek astronomy consult the magnificent 3-volume work by Otto Neugebauer, A History of Ancient Mathematical Astronomy, 1975. While Neugebauer has much less to say than Heath, it is far more technical. However, Part 2 is more interesting. Once the discussion turns to Aristarchus, Heath's analysis is quite relevant. Indeed, Heath's interpretation of one of the Scholia to Pappus of Alexandria (discussed on pages 317-318) is still a debated question. W. Knorr, The Ancient Tradition of Geometric Problems, 1986, agrees with Heath. Other modern scholars think Heath's conclusion is correct but his reading of the Scholia exceeds what the text can bear. Next Heath gives the Greek text and English translation of Aristarchus. This Greek text was used in the computerized data base Thesaurus Linguae Graecae. I bought a hard copy of this book over 30 years ago, and I believe that this is a work that should be preserved. Last night I needed to consult it!